In a conventional oil pumping rig, a polish rod is attached to a string of rods joined end to end below. The polish rod is suspended from a pumping rig, and moved up and down to operate the pumping mechanism down in the well in order to cause oil to flow upward out of the well. The polish rod passes through a carrier block and a rod rotator, and a clamp is attached to the polish rod above the rod rotator to prevent the polish rod from falling down into the well. Conventional clamps are of a clamshell construction, with two halves, hinged together, that surround the polish rod and are held together by bolts and nuts.